Former UFC welterweight champion Georges St-Pierre has torn his left ACL in training and will need surgery.

The Canadian gave up his title to take an indefinite leave of absence from the sport in December following a hard-fought, controversial split decision win over Johny Hendricks at UFC 167.

There was speculation that St-Pierre would retire following the win over Hendricks—his ninth consecutive title defense. The pair battled back-and-forth for all five rounds, the seventh straight bout that St-Pierre had gone 25 minutes in the cage. In his post-fight interview, St-Pierre stated that he needed to step away “for a little bit.”

When St-Pierre vacated the title, he left the door open for a return to the UFC, but no time table was given. Now, with the second significant knee injury in the last three years, the 32-year-old will face a much tougher road back to the Octagon. The fighter revealed surgery to repair the ACL will take place in the coming days.

St-Pierre tore his right ACL in 2011 and missed nearly all of 2012. However, he would return to defend his title against Carlos Condit at UFC 154, Nick Diaz at UFC 158 and the aforementioned Hendricks before his current hiatus.

Whether St-Pierre’s latest injury prevents the Canadian from competing for the UFC again, he will go down as one of the greatest fighters to ever set foot in the Octagon. During his nearly 12-year career, he has compiled a record of 25-2. Only six of his bouts have come outside of the UFC and 13 of his 21 bouts in the Octagon have been title contests. The Canadian has earned six “of the Night” bonuses in his career—all of which came with the belt on the line— including “Fight of the Night” honors against Hendricks.